JPS6314744B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a synthetic resin composition having excellent stability against heat and oxidation. Synthetic resins have excellent physical, chemical, and electrical properties, so they can be processed into molded products, pipes, sheets, films, etc. by various methods such as blow molding, extrusion molding, injection molding, or calendar processing. , used in many fields. It is well known that when synthetic resins are used alone, they deteriorate due to the action of heat and enzymes during processing or use, and their physical properties deteriorate significantly with phenomena such as softening, embrittlement, and discoloration. . In order to prevent such a phenomenon, various phenol-based, phosphorus-based, sulfur-based, and other antioxidants have conventionally been added and used during the manufacturing and processing steps of synthetic resins. Such phenolic antioxidants include:
For example, 2,6-di-t-butyl-4-methylphenol, 2,2'-methylenebis(4-methyl-6
-t-butylphenol), n-octadecyl-
β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, 1,3,5-trimethyl-2 ,4,
6-tris(3,5-di-t-butyl-4-hydroxybenzyl)-benzene, 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, pentaerythritol-tetrakis [β-(3,5-di-t-butyl-4-
Hydroxyphenyl propionate] and the like are known. However, these antioxidants are still not fully satisfactory in terms of thermal and oxidative stability. The present inventors have conducted various studies to solve these problems, and have found that by blending a specific phenolic compound into a synthetic resin, a heat and oxidation stabilizing effect that is far superior to that of conventional antioxidants can be obtained. This discovery led to the present invention. That is, the present invention provides a stabilized synthetic resin composition comprising a synthetic resin and a compound represented by the following general formula (). [In the formula, R represents an alkyl group having 1 to 4 carbon atoms. ] In the compound of the general formula () used in the present invention, R represents an alkyl group having 1 to 4 carbon atoms, and methyl and ethyl groups are preferable from the viewpoint of performance as an antioxidant, with methyl group being particularly preferable. Representative examples of compounds of general formula () used in the present invention are shown in Table-1.

[Table] Compounds of this general formula () have the following general formula () [In the formula, R represents an alkyl group having 1 to 4 carbon atoms. ] The compound shown by and the following structural formula () It can be produced by reacting the compound represented by the above, its lower alkyl ester, or its acid chloride by a known method. In the synthetic resin composition of the present invention, the amount of the compound of formula () is usually based on 100 parts by weight of the synthetic resin.
The amount is 0.001 to 5 parts by weight, preferably 0.01 to 2 parts by weight. In the present invention, in order to blend the compound of formula () into a synthetic resin, the known equipment and operation methods for mixing and blending stabilizers, pigments, fillers, etc. into thermoplastic resins can be applied almost as they are. The synthetic resin composition of the present invention may contain other additives such as ultraviolet absorbers, light stabilizers, antioxidants, metal soaps, pigments, and fillers. By adding sulfur-based compounds such as dilaurylthiodipropionate or distearylthiodipropionate or dimyristylthiodipropionate, among others, better thermal and oxidative stability can be achieved, as well as ultraviolet absorbers, hindered amine-based light By adding a stabilizer or the like, better weather resistance can be imparted. The synthetic resins stabilized by the present invention include:
Polyolefin resin, ABS resin, polystyrene resin, high impact polystyrene resin, polyamide resin, polyester resin, polycarbonate resin,
There are polyacetal resins, etc., and it is particularly effective for polyolefin resins. Next, the present invention will be explained in detail with reference to Reference Examples and Examples, but the present invention is not limited thereto. Reference example 1 Bis[2-(2'-hydroxy-3'-tert-butyl-5'-methylphenylmethyl)-4-methyl-6-tert-butylphenyl]3,3'-thiodipropionate [compound Example of production of No.-1] 4.28 g of 3,3'-thiodipropionic acid, 50 g of toluene, and thionyl chloride in a 300 ml four-necked flask.
Pour 11.0g and raise the temperature to 90℃ in a nitrogen stream.
Keep warm for 3 hours. After the reaction is complete, excess thionyl chloride is distilled off under reduced pressure together with the solvent. The dichloride of 3,3′-thiodipropionic acid and 2,2′-methylenebis(6-tert-
Dissolve 13.62g of butyl-4-methylphenol in 50g of toluene and keep at 10℃. A toluene solution of 4.9 g of triethylamine was added dropwise to this over 2 hours. After the addition, the triethylamine hydrochloride was filtered and the solvent was concentrated under reduced pressure to obtain 16.3 g of a crude product.
By recrystallizing this from n-hexane,
Obtain white crystals with mp 101.5-103.0℃. Elemental analysis C(%) H(%) S(%) Actual value 75.8 8.7 3.8 Measured value 75.9 8.6 3.9 Example 1 After mixing the following formulation with a mixer for 5 minutes,
The compound obtained by melt-kneading with a mixing roll at 180°C was molded into a sheet with a thickness of 1 mm using a hot press at 210°C, and a test piece of 40 x 40 x 1 mm was prepared. 30 of the specimen area in gear open at 150℃
The thermal and oxidative stability was evaluated by measuring the time until % embrittlement. The results are shown in Table-2. <Formulation> Unstabilized polypropylene resin 100 parts by weight Calcium stearate 0.1 Test compound Variables In the table, AO-1 to AO-6 indicate the following compounds. AO-1 2,6-di-t-butyl-4-methylphenol AO-2 n-octadecyl-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate AO-3 Pentaerythritol- Tetrakis [β-(3,5-di-t-butyl-4-
Hydroxyphenyl) propionate] AO-4 1,1,3-tris(2-methyl-4
-Hydroxy-5-t-butylphenyl)butane AO-5 1,3,5-trimethyl-2,4,6
-Tris(3,5-di-t-butyl-4
-Hydroxybenzyl)benzene AO-6 2,2'-methylenebis(4-methyl-
6-t-butylphenol)

【table】

[Table] Example 2 Put 100 parts by weight of unstabilized ABS resin powder into a crusher and disperse with an appropriate amount of methanol. 0.5 parts by weight of the test compound was added thereto, methanol was evaporated while mixing, and the resulting
ABS resin powder was used as the test sample. Thermal and oxidative stability was evaluated by the degree of discoloration of the ABS resin powder after aging in an open gear at 180°C. The results are shown in Table-3.

【table】

Claims (1)

[Scope of Claims] 1. A stabilized synthetic resin composition comprising a synthetic resin and a compound represented by the following structural formula. [In the formula, R represents an alkyl group having 1 to 4 carbon atoms. ]